Trane furnace error codes flash codes troubleshooting.
These are some common Trane furnace error codes.
Flashing fast: Normal call for heat
Continuous on: Replace control
Continuous off: Check for power
2 flashes: System lockout (no flame) or reversed polarity
3 flashes: Pressure switch problem
4 Flashes: Thermal (limit) protection off
5 Flashes: Flame sensed with gas valve off
Flashing Slow	 Normal - No call for Heat from thermostat
Flashing Fast	 Normal - Call for Heat from thermostat
Continuous ON	 Control Board Bad - needs replaced
Continuous OFF	 Check Power
2 Flashes	 System Lockout (Retries or Recycles exceeded)
3 Flashes	 Vent Pressure Switch Error
4 Flashes	 Open High Temperature Limit Device
5 Flashes	 Flame sensed when no flame should be present
6 Flashes	 115 Volt AC power reversed or Poor Grounding
7 Flashes	 Gas valve circuit error
8 Flashes	 Low flame sense signal
Flashing Slow	 Normal - No call for Heat from thermostat
Flashing Fast	 Normal - Call for Heat from thermostat
Continuous ON	 Control Board Bad - needs replaced
Continuous OFF	 Check Power
2 Flashes	 System Lockout (Retries or Recycles exceeded)
3 Flashes	 Vent Pressure Switch Error
4 Flashes	 Open High Temperature Limit Device
5 Flashes	 Flame sensed when no flame should be present
6 Flashes	 115 Volt AC power reversed or Poor Grounding
7 Flashes	 Gas valve circuit error
8 Flashes	 Low flame sense signal
9 Flashes	 Check ignitor circuit and line "N" to 24 VAC Common voltage ( < 2 volts)
(possible grounding problem)